PROBLEM TO BE SOLVED: To provide a ceramic-based decorative plate that has a good coating performance and appearance and has a sufficient suitability to an extreme low-humidity environment while ensuring a sufficient non-combustibility.SOLUTION: Provided is a decorative plate that comprises a sheet making gypsum board as the substrate and in which the surface of the substrate is polishing- and impregnation sealer-treated, and that has an organic coating layer comprising an anchor coat layer and a top coat layer in this order on the surface of the substrate, and characterized in that: (a) the anchor coat layer is surface polished and the coating thickness is 5 to 120 μm; (b) the coating thickness of the top coat layer is 5 to 40 μm; and (c) the coating thickness of the organic coating layer comprising anchor coat layer and top coat layer is 140 μm or less.